CVE-2026-109163 Apache HTTP Server: mod_vhost_alias 1 byte stack buffer overwrite (after CVE-2026-63292)
apache software foundation apache http server: no CVSS score yet. EPSS 0.2% estimated probability of exploitation activity in the next 30 days.
On this page
- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 16th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-121 Stack-based Buffer Overflow
- Published
- Modified
- Assigned by
- apache (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- apache software foundation:apache http server
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Apache Software Foundation Apache HTTP Server | from 2.4.69 through 2.4.70 |
Fix and patched versions
- Debian, Ubuntu, Red Hat, Alpine, Alpaquita: fixed package versions per release
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12 | apache2 | 2.4.71-1~deb12u1 | DEBIAN-CVE-2026-109163 |
| Debian | 13 | apache2 | 2.4.71-1~deb13u1 | DEBIAN-CVE-2026-109163 |
| Debian | 14 | apache2 | no fix listed | DEBIAN-CVE-2026-109163 |
| Ubuntu | 22.04:LTS | apache2 | 2.4.52-1ubuntu4.27 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | 24.04:LTS | apache2 | 2.4.58-1ubuntu8.19 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | 26.04:LTS | apache2 | 2.4.66-2ubuntu2.8 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | 26.10 | apache2 | 2.4.68-1ubuntu6.2 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | Pro:14.04:LTS | apache2 | 2.4.7-1ubuntu4.22+esm19 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | Pro:16.04:LTS | apache2 | 2.4.18-2ubuntu3.17+esm24 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | Pro:18.04:LTS | apache2 | 2.4.29-1ubuntu4.27+esm15 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Ubuntu | Pro:20.04:LTS | apache2 | 2.4.41-4ubuntu3.23+esm11 | UBUNTU-CVE-2026-109163 USN-9090-1 |
| Red Hat | hummingbird:1 | httpd, mod_lua, mod_ldap and 6 more | 0:2.4.71-0.1.hum1 | RHSA-2026:98998 |
| Red Hat | hummingbird:1 | mod_ssl, mod_proxy_html | 1:2.4.71-0.1.hum1 | RHSA-2026:98998 |
| Alpine | v3.21, v3.22, v3.23 and 1 more | apache2 | 2.4.71-r0 | ALPINE-CVE-2026-109163 |
| Alpaquita | stream | apache2 | 2.4.71-r0 | BELL-CVE-2026-109163 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Red Hat Security Data © Red Hat, Inc., CC BY 4.0; the Alpine secdb, CC BY-SA 4.0; BellSoft's OSV database, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · Red Hat · Alpine · Alpaquita.
Red Hat
Red Hat rates this Moderate.
This vulnerability is rated as Moderate impact because successful exploitation terminates worker processes, resulting in a denial of service without leading to remote code execution. In typical Red Hat deployments, dynamic mass virtual hosting using mod_vhost_alias is not enabled by default and requires explicit configuration directives such as VirtualDocumentRoot. Consequently, systems running standard web server configurations without mod_vhost_alias directives are unaffected by this issue.
If dynamic mass virtual hosting is not required, disable the `mod_vhost_alias` module:
1. Comment out the `vhost_alias_module` line in `/etc/httpd/conf.modules.d/00-base.conf` (or the respective configuration file loading the module):
```
# LoadModule vhost_alias_module modules/mod_vhost_alias.so
```
2. Restart the Apache HTTP Server service to apply the change:
```
systemctl restart httpd
```
Warning: Restarting or reloading the `httpd` service interrupts active connections. Disabling `mod_vhost_alias` will break virtual host resolution for deployments configured with directives such as `VirtualDocumentRoot` or `VirtualScriptAlias`.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | httpd | Not affected | |
| Red Hat Enterprise Linux 6 | httpd | Not affected | |
| Red Hat Enterprise Linux 7 | httpd | Not affected | |
| Red Hat Enterprise Linux 8 | httpd:2.4/httpd | Not affected | |
| Red Hat Enterprise Linux 9 | httpd | Not affected | |
| Red Hat Hardened Images | httpd | Affected | |
| Red Hat JBoss Core Services | jbcs-httpd24-httpd | Not affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-109163.